Orthodontic movement in the presence of advanced periodontal disease is rarely indicated. However in adolescents with juvenile periodontitis, function and esthetics may be compromised because of malocclusion. Phase-contrast microscopic monitoring of the subgingival microflora and nonsurgical, antimicrobial therapy were used to minimize periodontal complications commonly found with orthodontic movement of teeth with minimal osseous support in juvenile periodontitis subjects. Both limited and complete edgewise orthodontic movement were coordinated with periodontal therapy stressing maintenance of spirochetes, mitile rods and crevicular polymorphonuclear leukocytes at low or undetectable levels. After at least 2 years of followup, all orthodontic movement was successful without periodontal complications. This study provides the basis for a wider selection of therapeutic modes of treatment that can be employed on juvenile periodontitis subjects.